columbia sony 180 gram Lps - where from?

I've been searching around ebay and other places for some classic jazz, etc., and have come across a few Columbia 180 gram Lps, such as a couple of Thelonious Monk, Miles Davis, Bob Dylan. I've listened to the 2 Monk Lps I bought, and can't say I was blown away, although my memory of the Monk material is that it's not all that well-recorded anyway. (I don't have comparison CDs or Lps.)

Does anybody know anything about how these 180 gram Lps happened to get made, and whether, in general, they're all that good? I can say that the 2 Monk Lps were at least quiet (although in fairness to Columbia, most of the pressings from the 70's that I bought back then and still have are pretty quiet, too.)

Thanks